设计模式-适配器模式（类适配器、对象适配器、接口适配器详解）

//被适配的类
public class Voltage220V {
	public int output220V() {
		int src = 220;
		System.out.println("电压=" + src);
		return src;
	}
}

//适配接口
public interface IVoltage5V {
	public int output5V();
}

//适配器类
public class VoltageAdapter extends Voltage220V implements IVoltage5V {
	@Override
	public int output5V() {
		// TODO Auto-generated method stub
		//获取220V电压
		int srcV = output220V();
		int dstV = srcV / 44 ; //转成5v
		return dstV;
	}
}

//调用
public class Phone {
	public void charging(IVoltage5V iVoltage5V) {
		if(iVoltage5V.output5V() == 5) {
			System.out.println("电压是5v，可以充电");	
		    } else if (iVoltage5V.output5V() > 5) {
			System.out.println("电压大于5v，不可充电");
		}
	}
}

//测试
public class Client {
	public static void main(String[] args) {
		System.out.println("===类适配器测试===");
		Phone phone = new Phone();
		phone.charging(new VoltageAdapter());
	}
}

//被适配的类（不变）
public class Voltage220V {
	public int output220V() {
		int src = 220;
		System.out.println("电压=" + src);
		return src;
	}
}

//适配接口（不变）
public interface IVoltage5V {
	public int output5V();
}

//适配器类
public class VoltageAdapter  implements IVoltage5V {
	private Voltage220V voltage220V;
	//构造器
	public VoltageAdapter(Voltage220V voltage220v) {
		this.voltage220V = voltage220v;
	}

	@Override
	public int output5V() {
		int dst = 0;
		if(null != voltage220V) {
			int src = voltage220V.output220V();//获取220v电压
			dst = src / 44;
		}
		return dst;
	}
}

//调用（不变）
public class Phone {
	public void charging(IVoltage5V iVoltage5V) {
		if(iVoltage5V.output5V() == 5) {
			System.out.println("电压是5v，可以充电");	
		    } else if (iVoltage5V.output5V() > 5) {
			System.out.println("电压大于5v，不可充电");
		}
	}
}

//测试
public class Client {
	public static void main(String[] args) {
		System.out.println("===对象适配器===");
		Phone phone = new Phone();
		VoltageAdapter VoltageAdapter = new VoltageAdapter(new Voltage220V())；
		phone.charging(VoltageAdapter);
	}
}

//被适配的类（不变）
public class Voltage220V {
	public int output220V() {
		int src = 220;
		System.out.println("电压=" + src);
		return src;
	}
}

//适配接口
public interface IVoltage5V {
	public int output5V();
	public void m2(); //接口里冗余不重要的方法
	public String m3();
}
//抽象适配器
public abstract class AbsAdapter extends Voltage220V implements IVoltage5V{
    @Override //以空方法实现接口所有方法
    public int output5V() {
        return 0;
    }
    @Override
    public void m2() {
    }
    @Override
    public String m3() {
        return null;
    }
}

//调用（不变）
public class Phone {
	public void charging(IVoltage5V iVoltage5V) {
		if(iVoltage5V.output5V() == 5) {
			System.out.println("电压是5v，可以充电");
		} else if (iVoltage5V.output5V() > 5) {
			System.out.println("电压大于5v，不可充电");
		}
	}
}

//测试
public class Client {
	public static void main(String[] args) {
		System.out.println("===接口适配器===");
		AbsAdapter absAdapter = new AbsAdapter() { //匿名内部类的形式
			@Override //按需要重写接口方法
			public int output5V() {
				System.out.println("使用了output5V的方法");
				int srcV = output220V();
				int dstV = srcV / 44 ; //转成5v
				return dstV;
			}
		};
		Phone phone = new Phone();
		phone.charging(absAdapter);
	}
}